Pivoting tower crane



3,194,411 PIVOTING TOWER CRANE Pierre Durand, Lyon, France, assignor to Etablissements WeitzA S.A.Socits: Les Fils de Jules Weitz-Chautiers & Ateliers de Construction de Lyon-Weitz Reuuies, Lyon, France, a corporation of France Filed llilly 22, 1963, Ser. No. 296,650 Claims priority, application France, July 30, 1962, 42,789, Patent 1,338,439 4 Claims. (Cl. 212-46) The invention has for its object the provision of cranes including a vertical or substantially vertical mast constituted by superposed or telescopically interengaging elements and a sloping or horizontal jib pivotally secured to the mast, that is, pivoting tower cranes.

The invention has more particularly for its object the provision of erecting cranes of which the mast is pivotally secured to the frame while the jib is pivotally secured to the mast. For the erection of cranes of this type, there exist as a matter of fact, various methods which allow through the above-dened pivotal connection an unfolding or opening of the package formed by the crane when folded, which opening leads to an erection of the mast on the frame and to a hoisting of the jib.

The cranes referred to show the advantage of allowing an easy and speedy erection. However, their assembly requires the use of apparatus independent of the actual components of the crane. In other words, special driving mechanisms are required in addition to the components of the crane in order to allow a displaying of the crane.

The present invention removes this drawback and, according to a novel construction, it is possible with cranes of the type referred to to execute in practice the simultaneous erection of the mast and of the jib and to set them in the positions they are to occupy for operation of the machine, without requiring other parts or arrangements beyond those provided normally for the control of the different movements of the crane.

The method for using cranes according to the invention consists in folding the jib over the mast which is itself folded over the frame, the masses being distributed in a manner such that the center of gravity of the assembly of the folded mast and jib may be located between the pivotal axis connecting the mast with the frame and the outer end of the jib whereby said assembly has a tendency to automatically engage the ground through said outer end of the jib, so that the mast has a tendency to rock in a rising direction, while one of the driving mechanisms carried by the crane produces an opening of the angle between the mast and the jib so as to obtain in succession a raising of the mast on the frame and a hoisting of the jib.

The shifting of the center of gravity of the mast and jib assembly beyond the pivotal axis of the mast on the frame may be obtained either through a suitable distribution of the components of the crane, or else, through the application of masses on the jib.

Thus, by resorting merely -to one of the conventional driving mechanisms of the crane such as those serving for a raising of the jib, a hoisting of the load or a translational movement of the crane, it is possible to provide for the erection of the crane.

The invention will be readily understood While its advantages and other features will become apparent upon reading of the following description, reference being made to the accompanying diagrammatic drawings illustrating by way of example and in a non-limiting sense a preferred embodiment of a crane erected in accordance with the method disclosed hereinabove. In said drawings:

FIGS. 1 to 4 are diagrammatic elevational side views showing the crane respectively in its folded condition and during the main succesisve erection stages.

United States Patent .O

3,194,4ll Patented July I3, 1965 Ficje FIG. 5 is a diagrammatic elevational side view of a modified embodiment of the crane in its folded condition.

As illustrated, the ground is shown at 2, the crane carrying the frame at 3, the mast at 4 with its pivotal connection at 5 with the frame, while 6 designates the jib pivotally secured at 7 to the mast 4 and 8 designates the -tie or lifting blocks connecting the head of the mast with the jib 6.V Obviously, the mast 4 may be of any type Whatever and include telescopically interconnected or superposed elements and the crane may be equipped with a counterjib which is caused to rise While the mast is being erected in the manner disclosed hereinafter.

The crane being folded in the manner illustrated in FIG. 1, the center of gravity of the folded mast and jib assembly is located between the point 5 connecting the mast 4 with the frame 3 and the outer end of the jib 6 in a manner such that the assemblyy has a tendency to rock in a direction such that the outer end of the jib engages the ground 2; in other Words, the whole assembly has a tendency to rock in a direction leading to an erection of the mast; in order to cut out said rocking during any transportation of the folded crane, binding means which are not illustrated are obviously provided for holding the collapsed crane fast in the position illustrated in FIG. l.

When the crane is to be erected, the above-mentioned binding means are removed, which leads the assembly including mainly the mast and the jib 6 to rock in the manner disclosed hereinabove. In other words, it will engage the ground through the outer end of the jib 6 as illustrated in FIG. 2. When said position has been reached, the end of the jib 6 may be held in its groundengaging condition, or else, it may be held in position on intermediate means bearing or running over the ground, or again, in certain cases and chiefly when the jib 6 is short, it may be anchored to the ground.

The mast 4 having thus begun a rocking movement in a direction corresponding to its erection, the continuation and the end of its rising movement are obtained by opening gradually the angle a formed between the mast 4 and the jib 6 as illustrated in FIG. 3.

Said opening may be obtained in particular by adjusting the length of the lifting block system 8 connecting the head of the mast 4 with the jib 6; the mast 4 reaches thus finally its normal vertical position on the frame 3 while the end of the jib 6 remains in contacting relationship with the ground as illustrated in dot-and-dash lines in FIG. 4. Starting from said position, all that is required is to continue reducing the length of the lifting block system 8 with a view to raising the jib 6 into the position illustrated in solid lines in FIG. 4.

Obviously, the invention is not limited to the sole embodiment of the crane and to the sole erecting procedure disclosed hereinabove by way of example and it covers in contr-adistinction all the modifications thereof falling within the scope of the accompanying claims. Thus in particular and as illustrated in FIG. 5, the axis pivotally connecting the mast 4a with the frame 3a may be transferred through the presence of lateral arms 9 to a point 5a located at the upper level of the mast 4a, considered in its horizontal folded condition and at a short distance from the lower end of the mast. It is also possible to anchor the free end of the jib to the ground so that the mast may be erected by opening the angle formed between it and the jib without it being necessary for the latter to have been previously brought into contact with the ground through its free end.

What I claim is:

1. A pivoting tower crane comprising a support, a mast mounted for vertical swinging movement on and relative to the support about a first horizontal axis, a jib mounted for vertical swinging movement on and relative to the mast about a second horizontal axis, the mast and jib being positionable .a` lowered position in which the-mastpis"VV swung downand the jib is swung down on and overlies the mast, the mast in said Vlowered position extending from said rst axis in one direction, the jib in said lowered positionextending from said' second axis in the opposite i directionrom the mast?, said second axis `and the center of gravity of saidrnast and jib in said lowered'position being if wheeled carriage;Y

ANDRES H. NIELfsEm, Examiner.- Y 

1. A PIVOTING TOWER CRANE COMPRISING A SUPPORT, A MAST MOUNTED FOR VERTICAL SWINGING MOVEMENT ON AND RELATIVE TO THE SUPPORT ABOUT A FIRST HORIZONTAL AXIS, A JIB MOUNTED FOR VERTICAL SWINGING MOVEMENT ON AND RELATIVE TO THE MAST ABOUT A SECOND HORIZONTAL AXIS, THE MAST AND JIB BEING POSITIONABLE IN A LOWERED POSITION IN WHICH THE MAST IS SWUNG DOWN AND THE JIB IS SWUNG DOWN ON AND OVERLIES THE MAST, THE MAST IN SAID LOWERED POSITION EXTENDING FROM SAID FIRST AXIS IN ONE DIRECTION, THE JIB IN SAID LOWERED POSITION EXTENDING FROM SAID SECOND AXIS IN THE OPPOSITE DIRECTION FROM THE MAST, SAID SECOND AXIS AND THE CENTER OF GRAVITY OF SAID MAST AND JIB IN SAID LOWERED POSITION BEING DISPOSED ON OPPOSITE SIDES OF THE VERTICAL PLANE THAT INCLUDES SAID FIRST AXIS, AND MEANS ACTING BETWEEN THE MAST AND THE JIB TO SWING THE JIB UPWARDLY RELATIVE TO THE MAST. 